Were your relays the type with LEDs in them? I seem to recall mmoe having issues with relays of that type.

Why you only have 20v in the first place I am unsure however, if your power supply is outputting 24v then you should have 24v on the outputs.
Hood

The got fixed automatically overnight. Outputs giving out 24v but relays won't activate The relays don't have led, but your guess is right regarding current.  Any relay card advice

I would imagine most of the relay boards you can buy from the likes of eBay would be fine. I tend to use the Din rail mount type from Finder and they work fine.
Hood

Thanks for that advice, on rechecking found that first two groups of 4 only are affected, rest 2 groups are fine so probably the way ICs are gone.

Another problem is I have to keep adjusting DAC offset in PID tuning plugin   as the motor keeps running in some direction evertime on startup. How do I adjust this

If the axis drifts when Mach is started and the IP-A is in control then it is likely you have the encoder direction wrong, you can invert it in the plugin.
You should only need to press the button to adjust the DAC offset once.

Hood

Sitting with PID tuning, l have just not been able to do away with the oscillations. Attached is the parameters